Patent GB-190400261-A (GB)
Title: Improvements in Buttonhole Cutting and Stitching Machines.
Inventor: FAIRWEATHER WALLACE
Filed: 1904-01-05
Granted: 1904-11-03
Abstract: 261. Fairweather, W., [Singer Manufacturing Co.]. Jan. 5. Buttonhole -sewing ma c h i n e s; buttonholes, cutting; stopping - gear; work-supports.-To adapt buttonhole - sewing machines, of the type described in Specifications No. 20,358, A.D. 1902, and No 18,153, A.D. 1903, for cutting the buttonhole slit prior to the stitching operation, the cutter - operating device is arranged, in conjunction with the starting mechanism, so as to be thrown out of gear after the first ascent on starting the machine. Also a special auxiliary presser-plate closely embracing the buttonhole slit prevents the displacement of the work by friction of the needle &c. The swing arm 20, operated through an arm 25 by a treadle, carries the belt fork and a plunger 19 which engages a cam 23 on the main shaft to stop the latter positively when the belt is thrown on to the loose pulley. Attached to this plunger is a stud 15, which engages the horizontal portion of a slot 14 in the cutter actuating lever 13 when the swing arm is thrown over to start the machine. On the first movement of the machine, a trigger lever 39, carried by a crosshead 36, reciprocated by a crank 33 on the main shaft, engages a projection 38 fixed to the plunger, depressing the plunger and so operating the cutter lever 13. During this operation a pin 48 has held a pivoted cam-plate 50 out of contact with the trigger lever, but, at the lowest position, the pin passes the curved edge of the cam-plate and a spring 53 brings the cam-plate and trigger lever into face contact, so that, on all subsequent movements, the curved edge of the cam-plate acting upon the pin 48 will cause the trigger lever to swing out of contact with the plunger 19 and thus avoid any further depression of the cutter. When the swing arm is moved to the stop position again, an arm 54 projecting from it moves the camplate out of contact with the trigger lever in readiness for the next cycle. The work-plate 135 is vibrated laterally by a pivoted lever 136 actuated from the feed-wheel 32, and the sliding portion 75 is fed longitudinally by a slotted lever 141 similarly actuated. The throat-plate 146, which is slotted to receive the knife blade and to allow the reciprocation of the needle, is contained in a recess in the work-plate and is surrounded by the main clampplate 61 which is U-shaped and is attached to a plate 28<a> attached to the bifurcated plate which receives the pressure of the clamp-closing spring 63. The auxiliary presser-plate 64 is carried by a bar 68 which, being pivoted on a fixed pin 69, does not move longitudinally, but is free to vibrate in unison with the work-clamp under the influence of a bridle 73 attached to the work-clamp. A spring 71 presses the auxiliary plate on to the work, but as the projections 67 pass through slots in the work-clamp, Fig. 10, the plate is raised by the work-clamp when the latter is raised by the usual treadle connection. The underside of the auxiliary presser-plate 64 is bevelled at 156 to permit a slight lifting of the work so that, during the forward feed when the tendency is to form the purl away from the edge, the purl may be formed wholly on the edge of the slit. A small rib 155 is provided to open the slot slightly, and to clear away loose threads.